1. Field of the Invention:
The present invention relates to a rear-view mirror pivoting apparatus for use in a vehicle, and more particularly, to a rear-view mirror of the type which pivots a rear-view mirror supported in such a manner that it can pivots relative to a mirror box once in 2 seconds so as to eliminate a dead angle which cannot be viewed when a vehicle is turned to the left or the right and in which the rear-view mirror is automatically returned to a position at which it is used to view the rear of the vehicle after the vehicle has turned to the left or the right.
2. Description of the Related Art:
Japanese Utility Model No. 58-20421 filed by the present inventor proposes a left-turn rear-view mirror of the above-described type for use in a heavy-duty vehicle.
This conventional technique concerns a rear-view mirror through which a seat-occupant can view the dead angle portion generated on the left side of a vehicle when the vehicle makes a turn, in particular, when a heavy-duty vehicle makes a left turn; wherein it is characterized in that the mirror includes a casing whose upper end is closed by a lid plate and is opened at its front; a mirror disposed on the open side of the casing with its upper end rotatably supported on the lid plate by a shaft and its lower end supported on the lower end of the casing by a shaft; a supporting plate extending at the central portion of the casing in the horizontal direction with its one end fixed to a backing plate affixed on too the back side of the mirror, a spring being extended between the other end of the supporting plate and the back side of the casing; a motor fixed in such a manner that a shaft of the motor hangs from the under surface of the lid plate; and a crank shaft connected to the rotary shaft of the motor, the lower end of the crank shaft being received by an elliptical through-hole formed in the supporting plate with a bearing therebetween. The mirror is further characterized in that it has an upper flat portion, a lower curved portion bent toward the casing and the right and the left portions both curved toward the casing, the motor being connected to an energizing means for operating the motor in connection with the left turn signal provided on the side of the driver's seat.
In the above-described conventional rear-view mirror, the motor and the crank shaft for moving the mirror are directly coupled with each other without a reduction mechanism provided therebetween so as to allow the mirror to be returned by the spring.
Furthermore, the crank shaft is required to rotate against the urging force of the spring.
In consequence, an expensive low-speed, large-torque rotary motor, such as a multipolar synchronous motor or a step motor, is required.
Furthermore, since the mirror is pivotally supported on the casing at the latitudinal center thereof, it reflects only the car body, the view right behind thereof and the narrow left range near the car body, when it is pivoted.
In order to widen its range of vision, the angle of deflection of the pivot must be made sufficiently large and the deflecting speed of the pivot must be sufficiently increased, which is however inconvenient and dangerous to a driver.
Furthermore, since the crank shaft is inserted into the through-hole formed in the supporting plate extending from the mirror with the bearing therebetween, said supporting plate is readily rattled, and said mirror connected to said supporting plate readily moves due to the swing or vibrations of the car body making it difficult for the driver to check the rear view of the vehicle.